1. Field of the Invention
The invention relates to an apparatus for applying a liquid medium, more particularly, a flavor or menthol, to tobacco in a cigarette maker of the kind set forth in the preamble of claim 1.
In cigarette production it is known to add various materials to the tobacco for the purpose of improving certain properties of the finished cigarette, flavor and menthol being the best known materials, and are applied to the tobacco in the liquid condition.
It is important in this respect that the added material is distributed uniformly over the tobacco so that all cigarettes produced have the same properties.
In addition, the liquid medium itself needs to be added uniformly so that each and every cigarette has consistent smoking performance from the first to the last puff.
2. Description of Prior Art
For this purpose, DE 22 54 063 C3 discloses a method of producing cigarettes in which the liquid medium is sprayed onto the tobacco in the form of an aerosol downstream of the distributor and just before enwrapping the tobacco carpet with a garniture tape.
Another method reads from DE 38 44 620 C2 in which the liquid medium is sprayed onto the tobacco carpeted on the suction band of the cigarette maker. In this arrangement, the liquid conduit connecting the pump to the injector is required to have a diameter of less than 1 mm so that the response delay in adapting the volume of the liquid to the working speed of the cigarette maker is at a minimum. The injector for the liquid medium is positioned in the stack under the suction band at a location at which the thickness of the tobacco layer carpeted on the suction band corresponds to approximately half the thickness of the final tobacco carpet. The injector is inclined in the conveying direction of the carpeted tobacco, namely at an angle of approximately 45.degree. to the conveying direction, and the liquid medium is sprayed as an airless, concentrated jet of liquid onto the surface of the tobacco. The orifice of the injector is positioned at a distance from the surface of the tobacco.
A similar method reads from DE 38 21 677 C2.
An apparatus for applying a liquid medium, especially flavor or menthol, onto tobacco in a cigarette maker of the aforementioned kind is disclosed by U.S. Pat. No. 4,619,276 and comprises a conduit for supplying the liquid medium as well as a nozzle fed by the conduit, which is likewise disposed under the suction band of a cigarette former of the cigarette maker, and the liquid medium is sprayed, through the nozzle orifice, onto the tobacco.
To prevent the liquid medium from spotting the cigarette paper, the liquid medium is applied in the form of foam, this, however, necessitating a complicated conditioning of the liquid medium.
The orifice is distanced approximately 1 inch from the suction band, and is oriented either perpendicular or parallel to the suction direction of the tobacco. No details are given as to the distance between the nozzle orifice and the carpeted tobacco.
With all of these known methods, the same problem is encountered in actual practice: there is no preventing subsequent tobacco from also being sprayed and randomly carpeted in the stack or passage ledge region under the suction band, which leads to increased spotting of the cigarette paper. In addition to this, the stack under the suction band is also wetted with the liquid medium so that subsequent particles collect there and may be entrained at random which, likewise, results in spotting of the cigarette paper.
In addition, the location of the outlet orifice changes in the stack under the suction band, as does its angle of adjustment to the rod of tobacco being formed, this, on the one hand, differing from one type of maker to the other and, on the other, with a fluctuation in the application weight of the tobacco since the height of the tobacco rod forming at the spray point fluctuates correspondingly, so that, likewise, there is no preventing of intensified spotting.
An additional problem is that the orifice and its conduit are located in the upswept suction stream of tobacco, therefore, there is a risk that the tobacco will collect there, resulting in a tobacco "stopper" nuisance.